Tree nut allergy
Encyclopedia
Tree nut allergy is one of the most common types of food allergy
, affecting millions of people worldwide. It is a hypersensitivity to diet
ary substances from tree nut
s causing an overreaction of the immune system, which may lead to severe physical symptoms. Tree nuts include almonds, Brazil nuts, cashews, chestnuts, filberts/hazelnuts, macadamia nuts, coconut
, pecans, pine nuts (pignolia nuts), pistachios, and walnuts.
People with tree nut allergy are seldom allergic to just one type of nut, and are therefore usually advised to avoid all tree nuts, even though an individual may not be allergic to all varieties of tree nuts. Someone allergic to walnuts or pecans may not have an allergy to cashews or pistachios, even though close biological relatives often share related allergenic proteins. The severity of the allergy varies from person to person, and exposure can increase sensitization. For those with a milder form of the allergy, the raw nut protein usually causes a more severe reaction than the oil, and extra roasting or processing can reduce the allergic reaction. Those diagnosed with anaphylaxis
will have a more immediate mast cell reaction and be required to avoid all exposure to any allergen-containing products or byproducts, regardless of processing, as they are prone to even greater sensitivity. An allergy test or food challenge may be performed at an allergy clinic to determine the exact allergens. New immunotherapy
treatments are being developed for tree nut allergy.
Tree nut allergy is distinct from peanut allergy
, as peanut
s are considered legumes, whereas a tree nut is a hard-shelled fruit
of certain plants.
This allergy tends to be life-long; recent studies have shown that only about 9% of children outgrow their tree nut allergy.
Hazelnut has been used as a model tree nut in the study of tree nut allergies.
, the federal Food Allergen Labeling and Consumer Protection Act (FALCPA) requires that any packaged food product that contains tree nuts as an ingredient must list the specific tree nut on the label. Foods that almost always contain tree nuts include pesto
, marzipan
, Nutella
, baklava
, pralines, nougat
, gianduja
, and turrón
. Other common foods that may contain tree nuts include cereals, crackers, cookies, baked goods, candy, chocolates, energy/granola bars, flavored coffee, frozen desserts, marinades, barbecue sauces, and some cold cuts, such as mortadella
. Tree nut oils (especially shea nut) are also sometimes used in lotions and soaps. Asian and African restaurants, ice cream parlors, and bakeries are considered high-risk for people with tree nut allergy due to the common use of nuts and the possibility of cross contamination
.
Treatment usually involves an exclusion diet
and vigilant avoidance of foods that may be contaminated with tree nuts, nut particles, or oils. The most severe nut allergy reaction is anaphylaxis
, an emergency situation requiring immediate attention and treatment with epinephrine
.
Food allergy
A food allergy is an adverse immune response to a food protein. They are distinct from other adverse responses to food, such as food intolerance, pharmacological reactions, and toxin-mediated reactions....
, affecting millions of people worldwide. It is a hypersensitivity to diet
Diet (nutrition)
In nutrition, diet is the sum of food consumed by a person or other organism. Dietary habits are the habitual decisions an individual or culture makes when choosing what foods to eat. With the word diet, it is often implied the use of specific intake of nutrition for health or weight-management...
ary substances from tree nut
Nut (fruit)
A nut is a hard-shelled fruit of some plants having an indehiscent seed. While a wide variety of dried seeds and fruits are called nuts in English, only a certain number of them are considered by biologists to be true nuts...
s causing an overreaction of the immune system, which may lead to severe physical symptoms. Tree nuts include almonds, Brazil nuts, cashews, chestnuts, filberts/hazelnuts, macadamia nuts, coconut
Coconut
The coconut palm, Cocos nucifera, is a member of the family Arecaceae . It is the only accepted species in the genus Cocos. The term coconut can refer to the entire coconut palm, the seed, or the fruit, which is not a botanical nut. The spelling cocoanut is an old-fashioned form of the word...
, pecans, pine nuts (pignolia nuts), pistachios, and walnuts.
People with tree nut allergy are seldom allergic to just one type of nut, and are therefore usually advised to avoid all tree nuts, even though an individual may not be allergic to all varieties of tree nuts. Someone allergic to walnuts or pecans may not have an allergy to cashews or pistachios, even though close biological relatives often share related allergenic proteins. The severity of the allergy varies from person to person, and exposure can increase sensitization. For those with a milder form of the allergy, the raw nut protein usually causes a more severe reaction than the oil, and extra roasting or processing can reduce the allergic reaction. Those diagnosed with anaphylaxis
Anaphylaxis
Anaphylaxis is defined as "a serious allergic reaction that is rapid in onset and may cause death". It typically results in a number of symptoms including throat swelling, an itchy rash, and low blood pressure...
will have a more immediate mast cell reaction and be required to avoid all exposure to any allergen-containing products or byproducts, regardless of processing, as they are prone to even greater sensitivity. An allergy test or food challenge may be performed at an allergy clinic to determine the exact allergens. New immunotherapy
Immunotherapy
Immunotherapy is a medical term defined as the "treatment of disease by inducing, enhancing, or suppressing an immune response". Immunotherapies designed to elicit or amplify an immune response are classified as activation immunotherapies. While immunotherapies that reduce or suppress are...
treatments are being developed for tree nut allergy.
Tree nut allergy is distinct from peanut allergy
Peanut allergy
Peanut allergy is a type of food allergy distinct from nut allergies. It is a type 1 hypersensitivity reaction to dietary substances from peanuts causing an overreaction of the immune system which in a small percentage of people may lead to severe physical symptoms. It is estimated to affect...
, as peanut
Peanut
The peanut, or groundnut , is a species in the legume or "bean" family , so it is not a nut. The peanut was probably first cultivated in the valleys of Peru. It is an annual herbaceous plant growing tall...
s are considered legumes, whereas a tree nut is a hard-shelled fruit
Fruit
In broad terms, a fruit is a structure of a plant that contains its seeds.The term has different meanings dependent on context. In non-technical usage, such as food preparation, fruit normally means the fleshy seed-associated structures of certain plants that are sweet and edible in the raw state,...
of certain plants.
This allergy tends to be life-long; recent studies have shown that only about 9% of children outgrow their tree nut allergy.
Hazelnut has been used as a model tree nut in the study of tree nut allergies.
Prevention and treatment
In the United StatesUnited States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, the federal Food Allergen Labeling and Consumer Protection Act (FALCPA) requires that any packaged food product that contains tree nuts as an ingredient must list the specific tree nut on the label. Foods that almost always contain tree nuts include pesto
Pesto
Pesto is a sauce originating in Genoa in the Liguria region of northern Italy , and traditionally consists of crushed garlic, basil and pine nuts blended with olive oil and Parmigiano Reggiano and Fiore Sardo...
, marzipan
Marzipan
Marzipan is a confection consisting primarily of sugar and almond meal. Persipan is a similar, yet less expensive product, in which the almonds are replaced by apricot or peach kernels...
, Nutella
Nutella
Nutella is the brand name of a chocolate spread. Nutella, manufactured by the Italian company Ferrero, was introduced on the market in 1963. The recipe was developed from an earlier Ferrero spread released in 1944. Nutella is now sold in over 75 countries....
, baklava
Baklava
Baklava is a rich, sweet pastry made of layers of filo pastry filled with chopped nuts and sweetened with syrup or honey. It is characteristic of the cuisines of the former Ottoman Empire and much of central and southwest Asia....
, pralines, nougat
Nougat
Nougat is a variety of similar traditional confectioneries made with sugar and/or honey, roasted nuts , and sometimes chopped candied fruit. The consistency of nougat can range from soft and chewy to hard and crunchy depending on its composition, and it is used in a variety of candy bars and...
, gianduja
Gianduja (chocolate)
Gianduja is a sweet chocolate containing about 30% hazelnut paste, invented in Turin by Caffarel in 1852. It takes its name from Gianduja, a Carnival and marionette character who represents the archetypal Piedmontese, a native of the Italian region where hazelnut confectionery is common.Some...
, and turrón
Turrón
Turrón , torró , or torrone , or nougat is a confection, typically made of honey, sugar, and egg white, with toasted almonds or other nuts, and usually shaped into either a rectangular tablet or a round cake. It is frequently consumed as a traditional Christmas dessert in Spain and Italy. There are...
. Other common foods that may contain tree nuts include cereals, crackers, cookies, baked goods, candy, chocolates, energy/granola bars, flavored coffee, frozen desserts, marinades, barbecue sauces, and some cold cuts, such as mortadella
Mortadella
Mortadella is a large Italian sausage or cold cut made of finely hashed or ground, heat-cured pork sausage, which incorporates at least 15% small cubes of pork fat . Mortadella is a staple product of Bologna, Italy...
. Tree nut oils (especially shea nut) are also sometimes used in lotions and soaps. Asian and African restaurants, ice cream parlors, and bakeries are considered high-risk for people with tree nut allergy due to the common use of nuts and the possibility of cross contamination
Cross Contamination
Cross Contamination is an album by the rock bands Batmobile and Peter Pan Speedrock. It was released in 2008 by Suburban Records.-Track listing:#"Hellalujah"#"Go Satan Go"#"Killerspeed"#"Big Toy"#"Straight Back To Hormoneville"#"Transsylvanian Express"...
.
Treatment usually involves an exclusion diet
Dieting
Dieting is the practice of eating food in a regulated fashion to achieve or maintain a controlled weight. In most cases dieting is used in combination with physical exercise to lose weight in those who are overweight or obese. Some athletes, however, follow a diet to gain weight...
and vigilant avoidance of foods that may be contaminated with tree nuts, nut particles, or oils. The most severe nut allergy reaction is anaphylaxis
Anaphylaxis
Anaphylaxis is defined as "a serious allergic reaction that is rapid in onset and may cause death". It typically results in a number of symptoms including throat swelling, an itchy rash, and low blood pressure...
, an emergency situation requiring immediate attention and treatment with epinephrine
Epinephrine
Epinephrine is a hormone and a neurotransmitter. It increases heart rate, constricts blood vessels, dilates air passages and participates in the fight-or-flight response of the sympathetic nervous system. In chemical terms, adrenaline is one of a group of monoamines called the catecholamines...
.
See also
- AllergyAllergyAn Allergy is a hypersensitivity disorder of the immune system. Allergic reactions occur when a person's immune system reacts to normally harmless substances in the environment. A substance that causes a reaction is called an allergen. These reactions are acquired, predictable, and rapid...
- List of allergies
- AnaphylaxisAnaphylaxisAnaphylaxis is defined as "a serious allergic reaction that is rapid in onset and may cause death". It typically results in a number of symptoms including throat swelling, an itchy rash, and low blood pressure...
- Food allergyFood allergyA food allergy is an adverse immune response to a food protein. They are distinct from other adverse responses to food, such as food intolerance, pharmacological reactions, and toxin-mediated reactions....
- AsthmaAsthmaAsthma is the common chronic inflammatory disease of the airways characterized by variable and recurring symptoms, reversible airflow obstruction, and bronchospasm. Symptoms include wheezing, coughing, chest tightness, and shortness of breath...
- Peanut allergyPeanut allergyPeanut allergy is a type of food allergy distinct from nut allergies. It is a type 1 hypersensitivity reaction to dietary substances from peanuts causing an overreaction of the immune system which in a small percentage of people may lead to severe physical symptoms. It is estimated to affect...
External links
- Tree nut allergy at Food Allergy InitiativeFood Allergy InitiativeThe Food Allergy Initiative is a 501 non-profit organization founded in 1998 with the mission to fund food allergy research that seeks a cure, to improve diagnosis and treatment, and to keep patients safe through advocacy and education. FAI is the largest private source of funding for food...
- "Are Nut Bans Promoting Hysteria?" by Tana Parker-Pope at The New York Times (15 Dec 2008)